Rib hole-detector for revolving and stationary head rib knitting machines



E. VOSSEN Dec. 2, 1958 2,862,377 RIB HOLE-DETECTOR FOR REVOLVING AND STATIONARY HEAD RIB KNITTING MACHINES 4 Sheets-Sheet 1 Filed Oct. 18, 1954 Ill IHHII 7 Wm m W m mm A F. J M

Dec. 2, 1958 E. VOSSEN 2,862,377

RIB HOLE-DETECTOR FOR REVOLVING AND STATIONARY HEAD RIB KNITTING MACHINES Filed Oct. 18, 1954 4 Sheets-Sheet 2 W 1210 4 14-8 115 7 ii TRANS FORMER 306/ I2 VOLTS CONT ROLLER INVENTOR [OW/M 0 VOSJZW ATTORNEY Dec. 2, 1958 E. VOSSEN 2,862,377

RIB HOLE-DETECTOR FOR REVOLVING AND STATIONARY HEAD RIB KNITTING MACHINES Filed Oct. 18, 1954 4 Sheets-Sheet 5 232 [DIV/5W0 VOJSEN.

E. VOSSEN 2, 1958' 2,862,377 RIB HOLE+DETECTOR FOR REVOLVING AND STATIONARY I HEAD RIB KNITTING MACHINES 4 Sheets-Sheet 4 Filed Oct. 18. 1954 INVE N TOR EDWARD VOSSEN.

ATTORNEY.

United States Patent O RIB HOLE-DETECTOR FOR REVOLVING AND gTATIgNARY HEAD RIB KNITTING MA- Edward Vossen, Malverne, N. Y., assignor to Stop- Motion Devices Corp., Brooklyn, N. Y.

Application October 18, 1954, Serial No. 462,782

6 Claims. (Cl. 66166) This invention relates to a rib hole-detector for revolv ing and stationary head rib knitting machines. It also relates to the stop-motion devices which are associated with said hole-detector and Which said hole-detector actuates in order to stop said rib knitting machines upon the detection of a hole or similar defect in the knitted fabric. This is a continuation-inpart of my Patent No. 2,691,880 which was issued to me on October 19, 1954.

The ribhole-detector which is herein described and claimed is applicable to three kinds of rib knitting machines. One of these knitting machines is provided with a revolving head. In this. machine the knitted fabric is stationary in the sense that it does not revolve. The second machine is provided with a stationary head and here, of course, the knitted fabric does revolve. This machine has no take-up arms. The third machine isalso provided with a stationary head but in addition it is equipped with vertical revolving take-up arms. knitted fabric revolves with the revolving take-up arms. All three machines may be grouped under the broad heading or classification of circular knitting machines.

The rib hole-detector which comprises the present invention is universally adaptable to all three knitting machines above described. When it is installed in. the stationary head rib knitting machines where the knitted fabric revolves, it is held in a stationary position. When it is installed in the revolving head rib knitting machine where the knitted fabric is stationary, it is made to revolve with the revolving head and relative to the knitted fabric. In all cases, the rib hole-detector is mounted within the knitted fabric tube and its action is directed radially outwardly.

The rib hole-detector herein claimed may also be made to operate from the outside of the knitted fabric tube radially inwardly, if this should be desired. This would particularly be true where the knitted fabric revolves and in such case the rib hole-detector would be mounted stationary on the outside of the knitted tube.

More specifically, the rib hole-detector which comprises 4 this invention includes two basic elements: The first is a double ring frame which engages the knitted fabric to spread it taut for the hole detection process. The second is a hole-detector assembly which includes a plurality of probes or feelers which engage the knitted fabric in the area which is spread taut by the double ring frame. In some cases, the double ring frame and the hole-detector assembly are mounted together, the latter being supported In this machine the operative position.

by the former. In other cases, the double ring frame may be mounted within the knitted tube and the hole-detector assembly may be mounted outside of the tube. When the hole-detector assembly is mounted within the tube, its

probes or feelers press radially outwardly against the taut area of the tube. mounted on the outside of the knitted tube, its probes or feelers press radially inwardly against said taut area.

In all cases an electric switch mechanism is provided for stopping the knitting machine when a hole or similar Where the hole-detector assembly is I defectisencountered and detectedby one of the probes or feelers of the rib hole-detector. This switch mechanism is mounted on the outside of the knitted tube. Hence, it may be incorporated into the rib hole-detector when said detector is mounted outside said knitted tube but it must constitute a completely separate and independent device when the rib hole-detector is mounte within the knitted tube.

In the latter case it is necessary to providean actuating mechanism between the rib hole-detector on the inside of the knitted tube and the switch mechanism on the outside thereof. This actuating mechanism comprises two elements: One is mounted within the tube and the other is mounted outside of the tube. The inner element is actuated by the hole-detector. The outer element is actuated by the inner element. The switch mechanism is actuated by the outer element. Thus a chain reaction is set up when a hole or flaw is detected in the fabric, beginning within the knitted tube, permeating or passing through the wall of said tube, and ending outside of the tube. The inner element includes a bumper or plunger which is normally in retracted position. It is always under the influence of a spring, however, which tends to urge it radially outwardly and into engagement with the taut area of the knitted tube. (A trigger mechanism is also included which releases said bumper or plunger when a hole or other flaw is detected in the knitted tube. Upon the happening of this occurrence, the bumper or plunger shoots radially outwardly against the knitted tube, distorting or stretching it sufliciently to enable said bumper or plunger to project beyond the double ring frame. In this position, the bumper or plunger encounters an outside arm or the like which constitutes the outside element above mentioned and dislodges it from its normal or in- This has the effect of actuating the switch mechanism and stopping the machine.

Where the switch mechanism and the hole-detector are mounted together in a single assembly, there is no need for an actuating mechanism of the type last above described. Instead, the hole-detector acts directly upon the switch mechanism immediately and automatically upon the detection of a hole or other flaw in the knitted material. v

In both cases last mentioned, that is, in the case of the switch mechanism and the hole-detector being mounted together to form a single assembly and in the case of the hole-detector being mounted within the knitted tube and the switch mechanism being mounted outside of the knitted tube, re-setting means is provided in order to start the knitting machine and to re-activate the hole-detecting mechanism. In the case of the hole-detector and switch mechanism being incorporated into a single assembly, a manually operated handle is provided which is connected both to the hole-detector and to the switch mechanism. All that need be done to re-set said hole-detector and said switch mechanism is to pull upon the handle. This can very readily be done since in such case, the holedetectorv and switch mechanism assembly are located outside of the knitted tube within convenient 'reach of the operator of the machine. In the other case, the bumper or plunger may be engaged from the outside of the knitted tube in order to reset the hole-detector which is located within the tube. This is very simply done by merely pressing upon said bumper or plunger until it regains its retractedposition. Similarly, the arm on the outside of the knitted tube which the bumper or plunger engages through the knitted material when a holeis encountered is simply swung back to its normal position where it may be engaged by said bumper or plunger. This has the effect of re-setting the switch mechanism which in this case is also located outside of the knitted tube.

- The rib hole-detector herein described and claimed at:

fords many important advantages and possesses many important features. Among these advantages and fea tures may be listed the following:

(1) The double ring frame whichiengages the knitted material and holds it inproper position and in proper condition for the hole-detecting process is an extremely important element. In the first place, it takes the place of the conventional spreader rings which are today employed for the same purpose. These spreader rings are made in various sizes to fit the various sizes of knitted tubes. Each tube requires a spreader ring of corresponding size and a spreader ring made for any one size of knitted tube cannot be used for any other size of knitted tube. In the present invention, on the other hand, a single size double ring frame may be employed in connection with knitted tubes of every conventional diameter. It should of course be small enough to enter the smallest tube and this is the only prerequisite to its universal use. If it fits the smallest tube, it will fit all of the larger tubes.

It is not essential that the double ring frame be concentric with the knitted tube. It suflices that the curvature of the double ring frame approximate the curvature of the knitted tube. An important aspect of this double ring frame is its adjustability relative to the tubular material. It may be shifted toward or away from the knitted tube in order to compensate for the various sizes of knitted tube which maybe encountered.

(2) The adjustable feature of the double ring frame is important for an entirely different purpose. This feature renders it possible to adjust the pressure which the double ring frame exerts against the knitted tube. It is thereby possible to achieve any desired degree of tautness in the knitted material. This is important not only because permanent stretch or distortion of the knitted material can thereby be avoided but also because it is essential to the proper functioning of the whole defect detecting apparatus.

(3) Another important advantage of this double ring frame is the fact that it holds a relatively wide area of the knitted tube in spread or taut condition. In other words, the knitted material which at any particular moment is disposed between the two rings of the frame constitutes a relatively wide belt or zone which is maintained by said rings in taut condition. A taut zone or belt of this character cannot be achieved by the single spreader rings of the prior art.

(4) A further advantage resides in the fact that the two rings of the double rin'g frame are offset from each other to conform to the taper of the knitted tube. It is well known that the knitted tubes which circular knitting machines produce are not perfectly cylindrical in shape. Instead, they taper inwardly from relatively large proportions at their upper end to relatively small proportions at their lower end. It is this taper to which the double ring frame of the present invention conforms.

(5) Still another important feature is the vertical bar which links the two rings immediately adjacent the series of probes or feelers which said double ring frame supports. This vertical bar precisely positions thetaut belt of the knitted material relative to the probes or feelers. Said vertical bar is inclined to correspond to the taper of the knitted tube, just as the two rings of the double ring frame are offset for the same purpose. The vertical bar cooperates with the two rings of said frame to hold the knitted material so precisely in place that it is possible to set the probes or feelers most accurately and sensitively relative to said knitted material. This is essential to the precise functioning of the apparatus herein claimed. The vertical bar also serves another purpose: It helps prevent the knitted material from being pushed inwardly beyond the range of its normal stretch or elasticity when the bumper or plunger above mentioned is returned to its retracted position.

(6) An important advantage of the double ring frame is the double hearing which the two rings provide for the hole detecting mechanism, both when the mechanism is stationary and when it is in motion. The double bearing renders it possible to set the hole detecting mechanism very precisely relative to the knitted material and the double hearing will maintain such precise setting or adjustment indefinitely.

(7) The switch mechanism in the present device also provides important advantages over the prior art. It performs two functions: In the first place, it acts as a switch to stop the machine as soon as a hole or other similar. defect is detected. In the second place, it serves as a cut-off switch which disconnects the unit from the knock-off controller. This is important because the hole detecting mechanism would otherwise keep on knocking off the machine when the fabric is found to be faulty over a relatively large area, whereas this feature enables the operator of the machine to render the hole detecting mechanism inoperative until the fabric runs whole again. Once the fabric runs clear of defects, the switch mechanism may be reset to its normal position, ready to detect other defects in the fabric.

Preferred forms of this invention are shown in the accompanying drawing in which:

Fig. l is a vertical section through a revolving head rib knitting machine and the knitted tube which it produces, showing a rib-hole detector made in accordance with one form of this invention, said hole-detector being mounted within the knitted tube for revolving movement with the head of said knitting machine.

Fig. 2 is a fragmentary top view thereof.

Fig. 3 is a View similar to that of Fig. 2 but showing one of the probes or feelers caught in a hole in the knitted fabric and showing the bumper or plunger in forwardly projecting position as a result thereof.

Fig. 4 is an enlarged view of the hole detecting mechan'ism following its detection of a hole and showing the bumper or plunger in its forwardly projecting position in engagement with the knitted fabric.

Fig. 5 is a fragmentary enlarged front view of said hole detector.

Fig. 6 is a fragmentary vertical section showing the hole detecting mechanism within the knitted tube and the switch mechanism outside of the knitted tube which is actuated by the hole detecting mechanism when a hole is detected in the fabric.

Fig. 6A is a fragmentary top view of the mechanism shown in Fig. 6, but showing that the bumper or plunger may be disposed on the opposite side of the hole detector from the side which it occupies in the preceding figures of the drawing, said view being taken on the line 6A-6A of Fig. 6.

Fig. 6B is a sectional view showing the hollow spindle or shaft of another type of knitting machine having a revolving head and showing a switch mechanism mounted within the knitted tube and connected to the stop motion mechanism by means of a conductor which extends through said hollow spindle or shaft.

Fig. 7 is a top view of a hole detector made in accordance with a second form of this invention, showing it in engagement with the outside of a knitted tube which is produced by a stationary head rib knitting machine.

Fig. 8 is an enlarged front end view of said hole detector, looking in the direction of arrows 8, 8 of Fig. 7.

Fig. 9 is an enlarged side view of said hole detector, showing the switch mechanism thereon.

Fig. 10 is a view similar to that of Fig. 9 but showing the switch mechanism in closed position.

Fig. 11 is a wiring diagram showing the electric circuit of the hole detecting mechanism herein claimed.

Fig. 12 is' an enlarged sectional view showing modified form of double ring guides.

V Fig. 13 is a fragmentary perspective view showing the use of a single ring within the knitted tube, holding the tube taut for the hole detecting mechanism said mechanism being shown adjustably mounted on one of the S spokes, supporting said ring on the central shaft of a knitting machine.

Fig. 14 is a side view of said hole detecting mechanism and a sectional view of said ring, showing the hole detecting mechanism in actuated condition following the detection of a hole in the knittedtube.

Fig. 15 is a front view or" said hole detecting mechamsm.

Fig. 16 is a side view, partly in section, showing the switch mechanism which is actuated by said hole detector and showing its position relative to the knitted tube and the hole detector within said tube.

Fig. 17 is a fragmentary plan view showing the hole detector in engagement with a hole in the knitted tube.

Fig. 18 is a fragmentary plan view of the switch mechanism shown in Fig. 16.

Referring now to the first form of this invention as .shown in Figs. 1 to inclusive it will be seen that a conventional revolving head circular knitting machine It) is provided. The knitted tube 12 which is made on said machine is stationary in the sense that it does not revolve. -Within said tube is a vertically extending shaft 14 which is connected to the revolving head of the machine and which rotates therewith on its own longitudinal axis.

Secured to shaft 14 is a bracket 16 having arms 18. It will be noted that these arms support the double ring frame 20 and the latter, in turn, carries hole-detector 22 for engagement with the knitted tube 12. Double ring frame 20 comprises an upper ring member 24 and a lower ring member 26 which are connected at their respective end portions to blocks 28 and 30 and a pair of rods 32 and 33 which are secured to said blocks 28 and 30 by means of set screws 34. It will be seen that these rods 32 and 33 are in spaced parallel relation to each other and that they occupy a common horizontal plane.

I They are slidably mounted in blocks 36 of arms 18 of the bracket and set screws 38 are provided for securing said rods to said blocks. It is by means of set screws 38 that rods 32 and 33 may be adjustably positioned on bracket 16 relative to vertical shaft 14 and relative to the knitted tube 12. It is by this means that the double ring frame may be shifted into proper position relative to knitted tubes of various proportions. It is also by this means that the double ring frame may be made to apply greater or lesser pressure upon the knitted tube.

Ring members 24 and 26 may be cast integrally with blocks 28 and 30 and hence integrally with each other. If desired, they may be secured by conventional fastening means and methods to said blocks and in such case they would, of course, be separate and independent elements, either castor machined, as desired. But whether they are cast together or fastened together ring members 24 and 26 are maintained in spaced parallel relationship and occupying spaced horizontal planes which are situated above and below the common plane which rods 32 and 33 occupy. The leading edges of the two ring members are arcuate in shape as Figs. 2 and 3 clearly show. It will be seen that the two ring members are offset from each other, the upper ring memberv projecting slightly beyond the lower ring member. These two ring'members are offset to the same extent that the knitted tube 12 is tapered. See Fig. 1. Hence, the two ring members will exert a substantially equal force or pressure against the knitted tube.

Secured to the two ring members 24 and 26 is a vertically extending bar 40 which has horizontally extending arms 42 and 44 respectively. These arms abut the facing sides of the two ring members and they are secured to said ring members by means of screws 46 or any other suitable fastening means. Vertical bar 40 is positioned centrally of the two ring members and its outer face is substantially flush with the curved edges of said ring members. Consequently, vertical bar 40 is inclined in the same measure that the ring members are offset and to the same extent that the knitted tube 12 tapers. It will be seen in the drawing that the curved edges of ring members 24 and 26 are normally in engagement with the inner surface of knitted tube 12 and this is also true of the vertical bar 40. The knitted fabric is held relatively taut between the two ring members so that any holes or other defects of like nature which may happen to be formed therein will very readily be detected by the hole-detecting mechanism which will hereinafter be more fully described.

Hole-detector 22 is mounted between the two ring members'24 and 26 as Fig. 4 clearly shows. The ring detector is thereby supported both on top and on the bottom and it is thereby provided with a very secure and rigid anchorage. This is extremely important for the proper functioning of the device and particularly when it reacts to the detection of a hole in the knitted fabric. More specifically, hole-detector 22 includes a casing 48 which has a top wall 50, a bottom wall 52, and one side wall 54. The other side of said casing is open. The top and bottom walls of the casing are secured to the upper and lower ring members by means of screws 56. It is this casing which supports the moving parts of the hole-detecting mechanism.

Slots 58 are formed in the top and bottom walls of the casing and it will be understood that these slots are in registration with each other and extend longitudinally of the casing. A pin 60 projects through these slots and mounted on said pin, between the upper and lower walls of'the casing, is a block 62. Pin 64) serves as a pivot or pintle for said block 62, enabling the block to pivot into and out of the casing. See Fig. 3. It will also be noted that the two outwardly projecting ends of pin 60 are engaged by tension springs 64 and that the opposite ends of said springs are anchored to the top and bottom walls of the casing by means of rivets 66. These springs tend to pull pin 60 in the direction of the ring members 24 and 26, leftwardly, as viewed in Figs. 2 and 3. The reason for this will shortly become apparent.

Block 62 has a plurality of spaced parallel holes 68 formed therein and occupying said holes are tubular members 70. These tubular members are closed at both ends, their closed forward endsbeing shown in Fig. 5 of the drawing. Slots 72 are provided in the front closed ends of tubes 70 and probes or feelers 74 are slidably mounted in said tubes with their front ends projecting through said slots. The end portions of said probes or feelers are reduced for ready penetration into any holes or similar flaws which may be encountered in the knitted fabric. Within tubes 70 are springs (not shown) which act upon the probes or feelers and urge them resiliently forwardly. It is these springs which maintain the probes or feelers in tensioned engagement with the knitted fabric.

It will be seen that a pair of projections or bosses 78 are provided on the forward end of block 62. It will also be seen that a pair of catch members 80 are formed at the corresponding end of casing 48. When block 62 is swung into position within casing 48, catch members 80 engage bosses 78 and tend to prevent said block from swinging outwardly from said casing. The bosses are held in tensioned engagement with said catch members by means of springs 64 which act upon block 62 through pin 60.

Arrow 82 in Fig. 2 indicates the direction of movement of the entire assembly mounted on shaft 14, more specifically, bracket 16, double ring frame 20 and hole-detector 22. As this entire assembly revolves about the axis of shaft 14, probes or feelers 74 scan the knitted tube and when a hole 84 is encountered in said tube, the probe or feeler which encounters it will enter said hole as Fig. 3 clearly shows. Since the hole is formed in a stationary tube, further movement of the assembly last mentioned will produce the effect also shown in Fig. 3 of '2? block 62 swinging out of casing 48. This is the first step in the stop-motion chain of events which leads to the stopping of the knitting machine.

Secured to block 62 is a bar 86 which serves as a trigger with respect to a bumper or plunger 88. Bumper or plunger 88 is a J-shapecl member having a longitudinal portion 90 and an arcuate end portion 92. At the proper time, that is when a hole is detected in the knitted fabric, this bumper or plunger thrusts forwardly into engagement with said fabric as Figs. 3 and 4 clearly show. The effect of this action will shortly appear.

A block 94 is secured by means of screws 96 to casing 48 and it will be noted that said block has a channel formed therein to accommodate the longitudinal portion 90 of the bumper or plunger 88. Said longitudinal portion 90 is slidably movable through said channel in block 94 so that the bumper or plunger may move from its retracted position in Fig. 1 to its projected position in Fig. 4- and back again to its Fig. 1 position. A cross bar 98 is secured to the back end of longitudinal portion 90 of the bumper or plunger and a pair of coil springs 100 are secured at one end to said crossbar and at the opposite end to screws 102 on block 94. Thus it is, that the plunger or bumper is urged by said springs to its projected position shown in Fig. 4 and when said plunger or bumper is returned to its retracted position as shown in Fig. 1, this movement takes place against the action of springs 100 and it has the effect of loading said springs.

It has been said that bar 86 serves as a trigger which releases the bumper or plunger from its retracted position and enables it to move forwardly under the influence of springs 100. Bar 86 engages a second bar 104 through a slot 106 in casing 48. Bar 104 is pivotally secured to block 94 and a leaf spring 108 engages said pivoted bar 104 to hold it in engagement with bar 86 on block 62. A plate 110 is fastened to block 94 by means of screws 112 and it will be seen that said plate secures the leaf spring 108 to said block 94 and holds said leaf spring in engagement with bar 104.

It will be seen in Fig. 3 that a shoulder 114 is provided on bar 104. When the bumper or plunger is in its retracted position, shoulder 114 engages crossbar 98 and prevents the bumper or plunger from moving forwardly under the action of springs 100. When block 62 is caused to pivot to its Fig. 3 position, when a hole or other defect of like nature is encountered in the knitted fabric, bar 86 cams pivoted bar 104 outwardly until crossbar 98 clears shoulder 114. The bumper or plunger is now free to thrust forwardly under the action of springs 100 to its Fig. 4 position in engagement with the knitted fabric.

When it is desired to reset the mechanism last above described, the bumper or plunger is pushed backwardly, through the knitted fabric, until its back end encounters bar 86. Further backward movement of the bumper or plunger causes block 62 to pivot backwardly from its Fig. 3 position to its Fig. 2 position. Not only is block 62 caused to pivot as aforementioned, but it is also caused to slide backwardly a sufficient distance to enable its bosses 78 to clear the clips 80 of the casing. At the same time, pivoted bar 104 is rendered free to swing back from its Fig. 3 position to its Fig. 2 position and its shoulder 114 re-engages crossbar 08 to hold the bumper or plunger in retracted position.

It will be noted that all of the above action takes place between the two ring members 24 and 26 of the double ring frame. All of the pivoted parts above described are provided with double bearings, that is, with a hearing support on each side thereof. Not only is this true of the pivoted parts but it is also true of the casing 48 which supports them, the upper wall of said casing being secured to ring 24 and the lower wall to ring 26.

The next step in the chain of events which stops the knitting machine takes place outside of the knitted tube.

gate-aw See Fig. 6. It will be noted that the bumper or plunger 88 causes a bulge 116 (Fig. 4) to form in the knitted fabric, beyond vertical bar 40 and beyond the curved edges of ring members 24 and 26. The bumper or plunger is now in a position where it is able to encounter a pivoted arm 118 which is supported by a bracket'120. A set screw 12217 in said bracket engages said arm 118 and it is the means by which said arm may be adjustably positioned in said bracket. Bracket 120 is adjustably 'ecured to a shaft 122 which is rotatably supported by a second bracket 124. Said second bracket is mounted on a frame member 126 of the knitting machine. A collar 128 above bracket 124 and a second collar 130 below said bracket are secured to shaft 122 to prevent axial shifting or dislodgment thereof. When the bumper or plunger 88 strikes arm 118 through the bulge in the knitted tube, said arm is caused to swing from one position to another and thereby shaft 122 is also caused to turn on its longitudinal axis a corresponding angular distance.

A recess or depression 132 is formed in shaft 122 to accommodate a ball 134. This ball is mounted in a hole 136 formed in bracket 124. A compression spring 138 in said hole bears against ball 134 and holds it in tensioned engagement with shaft 122. A screw threaded plug 140 retains said spring in said hole. It .Will be understood that when ball 134 is in recess 132, shaft 122 will be tensionally held in its operative position shown in Fig. 6, ready for engagement with bumper or plunger 88. A positive force is required to dislodge said ball from said recess and thereby to free the shaft and arm 118 for angular movement. This force is provided by the bumper or plunger. A diametrically opposite recess 142 is also provided in shaft 122 so that when said shaft and its arm 118 are turned a full 180", ball 134 will enter said diametrically opposite recess 142 and said shaft and said arm will once again be resiliently locked in position and they will remain in such position until dislodged therefrom by a positive force. In this case, the force will be manually effected and directed and said shaft and its arm will thereby be returned to their Fig. 6 positions.

The top end of shaft 122, designated in the drawing as 122a, is reduced in size and cut down to the shape of a flat bar. Fiber insulation 144 is provided on both sides of said fiat end portion 122a to serve as electrical insulation. It will be noted in Figs. 6 and 611 that a fiber or plastic tube 146 is disposed in a vertical hole 148 in bracket 124. A rod 150 is rotatably mounted in said fiber or plastic tube and its upper end 150a is also reduced and cut away to the shape of a fiat bar. A pair of brass or copper leaves 152 is secured at one end to flat portion 150a of rod 150 and the opposite ends of said leaves abut fiber insulation 144. When arm 118 and shaft 122 are in their Fig. 6 and 6a positions, fiber insulation 144 will prevent leaves 152 from making electrical contact with flat end portion 122a of shaft 122.

When a defect is encountered in the knitted fabric, one of the probes or feelers will be caught in it and block 62 will be swung to one side of its casing 48. This will release bumper or plunger 88 for engagement with arm 118 and said arm will be swung laterally out of its Fig. 6 position. Flat end portion 122a will thereby be caused to engage leaves 152 and an electric circuit will thereby be closed in order to actuate the stop-motion mechanism of the knitting machine. The operator of the machine may now swing arm 118 a full from its Fig. 6 position until ball 134 seats itself in recess 142. This outward position of arm 118 provides two advantages: In the first place, it serves notice of a defect in the knitted fabric which must be cleared before the machine is set back into operation. In the second place, it prevents the hole detecting mechanism from knocking-off the machine before the operator of the machine has an opportunity to clear the knitted fabric. The reason for this is plain:

when arm 118 is disposed diametrically oppositeits Fig. 6

position, fiber pads 144 will prevent contact between flattened end portion 122a of shaft 122 and contact leaves 152. When the fabric is cleared, arm 118 is returned to its Fig. 6 position and it is once again ready for engagement with bumper or plunger 88 when another defect in the fabric is detected.

Fig. 6B shows a modified form of the hole detecting mechanism last above described, the modification being principally in its switch mechanism rather than in the hole detecting mechanism. It will be noted that a block 160 of insulating material is secured to casing 48 and a leaf type of contact member 162 is secured at one end to said block. The opposite end projects forwardly of crossbar 98 and it will be noted that the intermediate portion of said leaf is bowed to avoid contact with said crossbar when the latter is in its retracted position. When a hole is detected in the knitted fabric, the process above described will take place and the bumper or plunger will be thrust forwardly against the knitted fabric. The crossbar will, of course, move together with the bumper or plunger and it will then engage the free end of leaf 162. This will close the circuit to the stop motion mechanism, thereby stopping the knitting machine.

In this form of the invention, there is no need for arm 118 and for the switch mechanism which said arm controls. Instead, a conductor 164 is connected to contact leaf 162 and said conductor 164 projects up through the hollow shaft 166 of the knitting machine. It is then connected to the stop-motion mechanism in the usual manner. The sole difference, to the extent that concerns the present invention, between the knitting machine of Fig. 6B and the knitting machine of Fig. 1, is the difference between solid shaft 14 and hollow shaft 166. It patently impossible to draw a wire up through the solid shaft and it is therefore necessary to provide a switch mechanism on the outside of the knitted tube. In some of the more modern knitting machines, the central shaft is hollow and it is thereforepossible to connect the hole detecting mechanism to the stop motion mechanism by means of a conductor drawn through the hollow shaft. The bumper or plunger 88 is used in this form of the invention only for the purpose of resetting the hole detecting mechanism from outside the knitted fabric. It is not used to actuate a switch mechanism located outside the knitted fabric.

Turning now to the second form of this invention and to Figs. 7, 8, 9 and 10, it will be seen that a hole detector 200 is provided on the outside of knitted tube 202. This hole detector includes a casing 204 which has a block 206 connected to its back wall. A bracket 208 projects into a hole in block 206 and supports said block and said casing. It will be noted that this hole, designated 210 in the drawing, extends vertically of block 206 and a vertical portion 212 of bracket 208 projects into said hole. It is therefore possible to swing casing 204 about said vertical portion 212 of the bracket to any desired position. A set screw 214 or a pair of set screws are screwed into block 206 for engagement with said vertical portion 212 of the bracket to hold the casing in any desired position thereon.

Pivotally and slidably mounted in casing 204 is a block 216 which corresponds to block 62 of the first form of this invention. More specifically, block 216 has .a pair of pins 218 projecting outwardly therefrom on a .common axis. These pins project through registering slots 220 which are formed in the top and bottom Walls .222 of the casing. Since pins 218 are mounted in slots '220 it is possible for block 216 to engage both in pivotal and slidable movement in the casing. Springs 224 are provided adjacent walls 222 of the casing and one end of :said springs is secured to said walls by means of pins or rivets 226 and the opposite end of said springs is secured to pins 218. These springs are thereby enabled to act upon block 216 and to urge it forwardly in the direction of the knitted tube 202. The back wall 228 of the casing is pro- 10* vided at its front end with a pair of clips 230 which project in front of block 216 when said block is in its retracted position in the casing. The forward end of said block is provided with a pair of bosses 232 which are engageable with clips 230 to hold the block in retracted position in the casing. Springs 224 tend to hold said block 216 in its forwardmost position, that is, with its bosses 232 in tensioned engagement with clips 230 of the casing.-

This arrangement of parts is similar to the arrangementof parts of the first form of this invention above described" A plurality of holes 234 is formed in block 216, longi-- tudinally thereof, and in spaced, parallel relationship to each other. Fixed in said holes are tubes 236 which areheld in place therein by means of set screws 238. The forward ends of said tubes are provided with caps 240 andsaid caps have slots 242 formed therein to accommodate probes or feelers 244. These probes or feelers have reduced forward ends for ready penetration into holes or other similar defects in the knitted fabric. Springs (not shown) are provided in tubes 236 for engagement with probes or feelers 244 to urge them resiliently forwardly.

It will be noted in Fig. 9 that when the probes or feelers are in scanning engagement with the outside of the knitted tube, they assume staggered or offset positions relative to each other in order to adapt themselves to the taper of the knitted tube. When a hole is encountered by any one of these probes or feelers, its reduced forward end projects into said hole as Fig. 7 clearly shows. In the knitting machine, under discussion; the knitted tube rotates and the hole detector is maintained in a stationary position. Hence, when one of the probes or feelers enters a hole in the knitted tube, and said tube rotates in the direction of arrow 246, the effect will be to swing block 216 out of its casing to its dotted line position shown in Fig. 7. When this takes' place, the switch mechanism 248 on casing 204 is actuated and the knitting machine caused to stop. The switch mechanism will now be described.

A switch box 250, made of electrically non-conductive material, is secured to the outside of wall 228 of the casing by means of screws 252 and 254. Mounted within the switch boX is a pair of leaf springs 256 which are secured to a pair of binding posts 258. These leaf springs serve as electrical contact members with respect to a slidable contact member 260. This slidable contact member has a longitudinal portion which is slidably mounted in a channel 262 formed in wall 228 of the casing. It has a pair of sidewardly extending fingers 264 at its back end and a lug 266 at its forward end, projecting in the opposite direction from fingers 264. It will be noted that when the slidable contact member 260 moves backwardly, its fingers engage leaf springs 256, thereby closing the circuit which will hereinafter be described. Its lug 266 is engageable with the forward end of block 216 and when the block is in retracted position within the casing, said block prevents the slidable contact member from moving backwardly into engagement with the two leaf springs .256. When block 216 is pulled outwardly from its casing to its dotted line position in Fig. 7, it disengages lug 266 and thereby frees the slidable contact member for backward movement into engagement with the leaf springs.

This backward movement of the slidable contact member takes place under the influence of a tension spring 268. The forward end of said spring is connected to the slidable con-tact member by means of a pin or stud 270. This stud projects through a slot 272 formed in channel portion 262 of the back wall 228 of the casing and it is movable forwardly and backwardly through said slot. The back end of the spring is secured to said back wall of the casingby means of a pin or stud 274. Hence, when a hole is encountered in the fabric and block 216 is pulled out of engagement with lug 266, said slidable contact member is pulled backwardly into contact with the two leaf springs 256.

It; will be noted that spring 268 actsagainst springs 2.24 above mentioned. Springs. 224; tend to urge block 216. forwardly and spring 268. acts to pull the slidable contact member 260, and with it'said block 216, backwardly. The two springs 224 are, however, stronger than spring 268 and hence they prevail as long as block 216 and lug 266 are in engagement with each other. Nhen the block disengages the lug, spring 268 is free to pull the slidable contact member into engagement with leaf springs 256. It will be noted that a pair of pins 276 are fixed to the switch box 250 for engagement with leaf springs 256. These pins tend to prevent the leaf springs from engaging the slidable contact member prematurely.

The resetting mechanism for resetting both block 216 and the switch mechanism is manually operable by means of a knob 278 which is slidably movable on a bar 236 which is secured to block 206 of the casing. A wire 282 is secured at its back end to knob 278 by means of a set screw 284. The forward end of said wire is looped around a second wire 286 which is secured to the back end of block 216. When knob 278 is pulled backwardly on bar 236, its Wire 282 pulls upon block 216 and draws it backwardiy into the casing. It will be understood that the backward movement of block 216 is from its dotted line position in Fig. 7. Since wire 236 is offset from the axial center of block 216, the backward pull on said block through said wire has the effect of swinging it back from its angular position indicated by the dotted lines in Fig. 7 to its longitudinally aligned position shown in Figs. 8 and 10. This brings the forward end of block 216 into renewed engagement with lug 2.66 of the slidable contact member and when the knob is released, springs 224 will return block 216 to its forwarding extending position and by the same token slidable contact member 260 will also be thrust forward until its fingers 264 are out of engagement with leaf springs 256. The circuit is now open.

A bumper is provided to prevent the knob from being pulled backwardly beyond a predetermined point. This bumper comprises a plate 233 on back wall 228 of the casing, a laterally bent end piece 290 on said plate, a dog 292 which is secured to wire 232, still another wire 294 secured to said dog and a compression spring 296 which is mounted on wire 294. Dog 292 projects through a slot 298 in the back wall 228 of the casing and a registering slot 360 which is formed in plate 2%. When knob 278 is retracted on bar 280, the ends of spring 296 are brought into abutment with dog 22 and end piece 296. The movement of said dog toward said end piece will be limited by spring 296 and so will the backward movement of knob 278, wire 282 and block 216.

End piece 290 and its plate 283 also perform another extremely important function. When a long run of defective material is encountered and the knitting machine is stopped as soon as the first hole is detected, it becomes necessary to run the machine until the fabric clears without interference on the part of the hole-detecting mechanism. This can be effected by simply pushing end piece 294? forwardly until the slidable contact member 260 disengages the fixed contact members 256. The machine may now be run without interruption until the fabric clears. Knob 278 may then be pulled backwardly to reset both the hole-detecting mechanism and the switch mechanism. Both will be reset simultaneously and without any danger of the operator of the machine resetting the one while forgetting to reset the other.

Fig. 11 shows an electrical diagram of the electrical system controlled by the hole-detecting mechanism herein described and claimed. In the diagram, reference characters 330 and 362 represent conventional stop-motion devices of a conventional circular knitting machine. The reference character 394 represents a hole-detecting device made in accordance with this invention. It will be noted that the high side of a transformer 306 is connected by conductors 308 and 310 to a suitablesource of alternating electric current. Conductors 312 and 314 are con; nected to the low side of the transformer. It will be noted that conductor 31 4--i s connected by means of conductors 316, 318 and 32d respectively to stop-motion devices-300 and 302 hole-detector 304. Reference character 322 indicates the ground connection of holedetector 304. A second conductor 324 is connected to hole-detector 30 4 and to one side of a signal bulb 326. Another conductor 328 is connected to the opposite side of the bulb and it is also connected, together with condoctor 312, to a controller 330. A slidably mounted rod 332 is controlled by said controller and said rod is connected in conventional manner to the clutch of the knitting machine so that movement of said rod in one direction stops the machine and movement in the opposite direction frees the machine for further operation.

The controller is conventional and its rod 332 is springurged for movement in the direction which enables it to stop the machine. When one of the probes of holedetector 3434 is caught in a hole in the knitted fabric, one of the above described switch mechanisms (for example, switch members 256 and 26% in Figs. 9 and 10) which is connected to said hole-detector closes and grounds the unit. The circuit to the controller is thereby closed through the ground and an electro-magnet (not shown). in the controller actuates a release mechanism which releases rod 332 for spring-urged movement in the direction required for stopping the machine. A switch (not shown) in the controller is also actuated when the electro-magnet is energized and the controller circuit through the ground is thereby broken. The signal light is now energized and its flashes to call the attention of the operator of the machine to the fact that the fabric is defective and the machine is stopped.

Fig. 12 shows a variation in construction of the double ring guide which engages the knitted tube and holds it taut for the hole-detecting procedure. The double ring guide first above described has an upper and a lower ring member which are offset from each other to conform to the curvature or taper of the knitted tube. It is possible to conform the double ring guide to the knitted tube without oflsetting the two ring members from each other and this is shown in Fig. 12. It will there be seen that a double ring guide is provided which has an upper ring member 400, a lower ring member 492, a pair of end blocks 466 to which the end of said ring members are secured and a vertical bar 404 which extends from the upper ring member 400 to the lower ring member 492 at the forward or operative edges of said ring members. These forward or operative edges register with each other since the upper and lower ring members are not offset fromeachother in any respect whatsoever.

Rods 408 correspond to rods 32 and 33 of the first form of this invention. At their back ends they are supported by a bracket such as bracket 16. At their forward ends they are provided with enlarged circular portions 410 which are provided with centered holes to accommodate bolts 412. These bolts secure blocks 406 to circular enlargements 410 of rods 408. it is possible by loosening these bolts to swivel or pivot blocks 406 about the axis of said bolts. Since the two ring members 409 and 402 are secured to blocks 406, the effect is to cause them as well as said blocks to pivot about bolts 412. This pivoting movement enables the double ring guide to conform to the curvature or taper of the knitted tube 12 as Fig. 12 clearly shows. in other words, the double ring guide shown in Fig. 12 is adjustable to the taper or curvature of the-knitted tube, whatever that taper or curvature may be.

Turning now to Figs. 13 to 18 inclusive, it will be observed that a single ring may be employed in place of the double ring 24, 26 above described, the purpose be ing the same. Mounted on central shaft 14 is a hub 5% which is'adjnstably secured to said shaft by means of a set screw'StlZor the like. Projecting radially outwardly from said hub 500 is a plurality of arms or spokes 504 and mounted on the outer ends of said arms or spokes is a ring 506, the axial center of said ring being the longitudinal axis of shaft 14.

Slidably mounted on one of the spokes 504 is a bracket consisting of an upper member 508 and a lower member 510 and fastening means for holding said members together. It will be noted that each of these members is grooved to receive the spoke 504 and it will be understood that the bracket as a whole, consisting of these two members fastened together, is slidably movable longitudinally of the spoke on which it is mounted and it is also angularly movable about said spoke. A set screw 512 is provided in the lower member 510 of the bracket to engage the spoke and thereby to lock the bracket in any selected or required position. It will be understood from the split nature or construction of said bracket that it may be removed from one spoke 504 and placed on another. It will also be understood that several such brackets may be employed in the same knitting machine, if such be desired, each one occupying a separable spoke.

Mounted on upper member 508 of the bracket is hole detector 514. This hole detector is basically similar to hole detector 22 above described. It is provided with an actuating arm 516 which is engageable with the knitted tube 12, when a hole is encountered by one of the probes 518, to actuate arm 118 of the switch mechanism. See Fig. 14.

Since hole detector 514 is mounted on bracket 508, 510, it will be understood that the position of said hole detector with respect to ring 506 and to the knitted tube 12 may be adjusted by simply adjusting the position of said bracket on the spoke or arm 504 on which it is mounted.

The foregoing is illustrative of preferred forms of this invention. It will be understood and appreciated that these preferred forms may be modified and other forms may be provided within the broad spirit of the invention and the broad scope of the claims.

I claim:

1. In a circular knitting machine having a central shaft extending vertically thereof, a support for a hole detector for detecting holes in the knitted tube made on said machine, said support comprising a hub which is adjustably secured to said vertical shaft, a plurality of radially extending arms mounted on said hub, a ring supported at the outer ends of said arms, coaxially with said vertical shaft, said ring being of a diameter to engage the inside of said knitted tube to hold it taut, a bracket which is adjustably mounted on one of said arms, and a hole detector mounted on said bracket, said bracket being adapted to support said hole detector in operative position relative to said knitted tube.

2. In a circular knitting machine in accordance with claim 1, wherein the hole detector comprises a casing, a pivotally and slidably mounted block in said casing, a plurality of spring-urged probes slidably mounted in said block, a pair of springs connected to said casing and said block and urging said block forwardly in said casing 14 and a pair of clips which hold the block in non-pivoted position within the casing.

3. In a circular knitting machine in accordance with claim 1, wherein the hole detector comprises a casing, a pivotally and slidably mounted block in said casing, a plurality of spring-urged probes slidably mounted in said block, a pair of springs connected to said casing and said block and urging said block forwardly in said casing and a pair of clips which hold the block in nonpivoted position within the casing, a handle being connected to the back of the block for retracting said block against the action of said springs, said handle being connected to a part of said block which is laterally spaced from its pivotal center, whereby retraction of said block from its pivoted position by said handle causes the block to swing back to non-pivoted position.

4. In a circular knitting machine in accordance with claim 1, wherein the hole detector comprises a casing, a pivotally and slidably mounted block in said casing, a plurality of spring-urged probes slidably mounted in said block, a pair of springs connected to said casing and said block and urging said block forwardly in said casing and a pair of clips which hold the block in nonpivoted position within the casing, an insulated switch block being mounted on the casing, a spring-urged contact member being slidably mounted on the casing, its spring action urging it to move backwardly, a catch on said contact member which engages the forward end of the block when the block is in its non-pivoted position to prevent backward movement of said contact member, anda pair of fixed contact members supported by said insulated switch block a spaced distance behind the slidable contact member, whereby pivotal movement of the first mentioned block out of the casing releases the catch and enables the slidable contact member to move under its spring action into engagement with said fixed contact members.

5. In a circular knitting machine in accordance with claim, 1, wherein the hole detector comprises a plurality of spring-urged probes mounted side by side for engagement with said knitted tube, each of spring-urged probes being individually movable longitudinally of itself into any hole in the knitted tube which it may encounter.

6. In a circular knitting machine in accordance with claim 1, wherein the bracket comprises a pair of grooved members which engage a radial arm between them in their respective grooves, said members being fastened together and one of said members being provided with a clamp screw which clamps them to said radial arm in any selected position thereon, both longitudinally and angularly of said radial arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,570,995 Vossen Oct. 9, 1951 2,571,211 Crawford et a1. Oct. 16, 1951 

